Our aims were to measure gastric and small bowel transit of radiolabeled chow or liquids in rats and to assess the effect of pharmacologically induced chronic sympathectomy of at least 5 weeks duration. Three series of experiments were performed. In series I, four rats in each group underwent i.p. chloral hydrate anesthesia, tracheostomy with intubation and mechanical ventilation: they received by gavage 1.0 g rat chow dissolved in 1.5 ml saline labeled with 1.0 mCi 99mTc-DTPA In series II, four rats in each group were anesthetized with only i.p. chloral hydrate and received 1.5 ml labeled saline. Rats were placed on a gamma camera for dynamic acquisition of 1-min images for 7 h in series I, and 4 h in series II. Activity was quantitated in stomach and cecum; gastric emptying was analyzed by the power exponential model. In series III, four rats in each group were studied for 1 h on gamma camera and sacrificed after 5 h. At the end of each study, the stomach, small bowel, cecum and colon were removed and radioactivity counted in each organ in a dose calibrator. Quantitation of radioactivity by gamma camera was highly accurate: labeled chow in the stomach at 7 h was identical by external camera and counting of the excised organ (linear regression slope = 1.01, r = 0.97, P < 0.0001). Similar precision was observed with labeled liquids (slope = 0.93, r = 0.93, P = 0.001). Chow emptied slower than liquid in both groups (P = 0.048). Ileocecal movement of isotope occurred by bolus transfers. Chemical sympathectomy did not alter gastric emptying or small bowel transit. In conclusion, gastric emptying and cecal filling in rats can be accurately quantitated by dynamic scintigraphy. The rat stomach discriminates between solids and liquids; cecal filling occurs by bolus transfers. Chronic guanethidine treatment, as a model of sympathectomy, does not alter upper gastrointestinal transit.
- Gastrointestinal and ileocolonic transit
- Sympathetic denervation
ASJC Scopus subject areas
- Clinical Neurology